" On that note, does an act have to criminal intent or is the execution of the act enough to be a crime? "
When the Sexual Offences Act 2003 draft was first presented for public consultation - it was quickly noticed that "indecent exposure" had been redefined. In the previous law it was "intent to cause alarm/distress".
In the new draft it was merely "to cause alarm/distress" - with a further modification that the judgement was made on the basis of a hypothetical "most vulnerable" person - rather than an actual observer.
Sections of the drafting committee justified the removal of "intent" because "there currently aren't enough convictions". After protests the "intent" was put back in for the wording of the act. I am not sure if the "hypothetical" victim status was retained.